1 files changed, 409 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-htc-egpio.c b/drivers/gpio/gpio-htc-egpio.c
new file mode 100644
index 000000000..a40bd5667
--- /dev/null
+++ b/drivers/gpio/gpio-htc-egpio.c
@@ -0,0 +1,409 @@
+/*
+ * Support for the GPIO/IRQ expander chips present on several HTC phones.
+ * These are implemented in CPLD chips present on the board.
+ *
+ * Copyright (c) 2007 Kevin O'Connor <kevin@koconnor.net>
+ * Copyright (c) 2007 Philipp Zabel <philipp.zabel@gmail.com>
+ *
+ * This file may be distributed under the terms of the GNU GPL license.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/platform_data/gpio-htc-egpio.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/gpio/driver.h>
+
+struct egpio_chip {
+	int              reg_start;
+	int              cached_values;
+	unsigned long    is_out;
+	struct device    *dev;
+	struct gpio_chip chip;
+};
+
+struct egpio_info {
+	spinlock_t        lock;
+
+	/* iomem info */
+	void __iomem      *base_addr;
+	int               bus_shift;	/* byte shift */
+	int               reg_shift;	/* bit shift */
+	int               reg_mask;
+
+	/* irq info */
+	int               ack_register;
+	int               ack_write;
+	u16               irqs_enabled;
+	uint              irq_start;
+	int               nirqs;
+	uint              chained_irq;
+
+	/* egpio info */
+	struct egpio_chip *chip;
+	int               nchips;
+};
+
+static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg)
+{
+	writew(value, ei->base_addr + (reg << ei->bus_shift));
+}
+
+static inline u16 egpio_readw(struct egpio_info *ei, int reg)
+{
+	return readw(ei->base_addr + (reg << ei->bus_shift));
+}
+
+/*
+ * IRQs
+ */
+
+static inline void ack_irqs(struct egpio_info *ei)
+{
+	egpio_writew(ei->ack_write, ei, ei->ack_register);
+	pr_debug("EGPIO ack - write %x to base+%x\n",
+			ei->ack_write, ei->ack_register << ei->bus_shift);
+}
+
+static void egpio_ack(struct irq_data *data)
+{
+}
+
+/* There does not appear to be a way to proactively mask interrupts
+ * on the egpio chip itself.  So, we simply ignore interrupts that
+ * aren't desired. */
+static void egpio_mask(struct irq_data *data)
+{
+	struct egpio_info *ei = irq_data_get_irq_chip_data(data);
+	ei->irqs_enabled &= ~(1 << (data->irq - ei->irq_start));
+	pr_debug("EGPIO mask %d %04x\n", data->irq, ei->irqs_enabled);
+}
+
+static void egpio_unmask(struct irq_data *data)
+{
+	struct egpio_info *ei = irq_data_get_irq_chip_data(data);
+	ei->irqs_enabled |= 1 << (data->irq - ei->irq_start);
+	pr_debug("EGPIO unmask %d %04x\n", data->irq, ei->irqs_enabled);
+}
+
+static struct irq_chip egpio_muxed_chip = {
+	.name		= "htc-egpio",
+	.irq_ack	= egpio_ack,
+	.irq_mask	= egpio_mask,
+	.irq_unmask	= egpio_unmask,
+};
+
+static void egpio_handler(struct irq_desc *desc)
+{
+	struct egpio_info *ei = irq_desc_get_handler_data(desc);
+	int irqpin;
+
+	/* Read current pins. */
+	unsigned long readval = egpio_readw(ei, ei->ack_register);
+	pr_debug("IRQ reg: %x\n", (unsigned int)readval);
+	/* Ack/unmask interrupts. */
+	ack_irqs(ei);
+	/* Process all set pins. */
+	readval &= ei->irqs_enabled;
+	for_each_set_bit(irqpin, &readval, ei->nirqs) {
+		/* Run irq handler */
+		pr_debug("got IRQ %d\n", irqpin);
+		generic_handle_irq(ei->irq_start + irqpin);
+	}
+}
+
+static inline int egpio_pos(struct egpio_info *ei, int bit)
+{
+	return bit >> ei->reg_shift;
+}
+
+static inline int egpio_bit(struct egpio_info *ei, int bit)
+{
+	return 1 << (bit & ((1 << ei->reg_shift)-1));
+}
+
+/*
+ * Input pins
+ */
+
+static int egpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct egpio_chip *egpio;
+	struct egpio_info *ei;
+	unsigned           bit;
+	int                reg;
+	int                value;
+
+	pr_debug("egpio_get_value(%d)\n", chip->base + offset);
+
+	egpio = gpiochip_get_data(chip);
+	ei    = dev_get_drvdata(egpio->dev);
+	bit   = egpio_bit(ei, offset);
+	reg   = egpio->reg_start + egpio_pos(ei, offset);
+
+	if (test_bit(offset, &egpio->is_out)) {
+		return !!(egpio->cached_values & (1 << offset));
+	} else {
+		value = egpio_readw(ei, reg);
+		pr_debug("readw(%p + %x) = %x\n",
+			 ei->base_addr, reg << ei->bus_shift, value);
+		return !!(value & bit);
+	}
+}
+
+static int egpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct egpio_chip *egpio;
+
+	egpio = gpiochip_get_data(chip);
+	return test_bit(offset, &egpio->is_out) ? -EINVAL : 0;
+}
+
+
+/*
+ * Output pins
+ */
+
+static void egpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	unsigned long     flag;
+	struct egpio_chip *egpio;
+	struct egpio_info *ei;
+	int               pos;
+	int               reg;
+	int               shift;
+
+	pr_debug("egpio_set(%s, %d(%d), %d)\n",
+			chip->label, offset, offset+chip->base, value);
+
+	egpio = gpiochip_get_data(chip);
+	ei    = dev_get_drvdata(egpio->dev);
+	pos   = egpio_pos(ei, offset);
+	reg   = egpio->reg_start + pos;
+	shift = pos << ei->reg_shift;
+
+	pr_debug("egpio %s: reg %d = 0x%04x\n", value ? "set" : "clear",
+			reg, (egpio->cached_values >> shift) & ei->reg_mask);
+
+	spin_lock_irqsave(&ei->lock, flag);
+	if (value)
+		egpio->cached_values |= (1 << offset);
+	else
+		egpio->cached_values &= ~(1 << offset);
+	egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg);
+	spin_unlock_irqrestore(&ei->lock, flag);
+}
+
+static int egpio_direction_output(struct gpio_chip *chip,
+					unsigned offset, int value)
+{
+	struct egpio_chip *egpio;
+
+	egpio = gpiochip_get_data(chip);
+	if (test_bit(offset, &egpio->is_out)) {
+		egpio_set(chip, offset, value);
+		return 0;
+	} else {
+		return -EINVAL;
+	}
+}
+
+static int egpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+	struct egpio_chip *egpio;
+
+	egpio = gpiochip_get_data(chip);
+
+	if (test_bit(offset, &egpio->is_out))
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static void egpio_write_cache(struct egpio_info *ei)
+{
+	int               i;
+	struct egpio_chip *egpio;
+	int               shift;
+
+	for (i = 0; i < ei->nchips; i++) {
+		egpio = &(ei->chip[i]);
+		if (!egpio->is_out)
+			continue;
+
+		for (shift = 0; shift < egpio->chip.ngpio;
+				shift += (1<<ei->reg_shift)) {
+
+			int reg = egpio->reg_start + egpio_pos(ei, shift);
+
+			if (!((egpio->is_out >> shift) & ei->reg_mask))
+				continue;
+
+			pr_debug("EGPIO: setting %x to %x, was %x\n", reg,
+				(egpio->cached_values >> shift) & ei->reg_mask,
+				egpio_readw(ei, reg));
+
+			egpio_writew((egpio->cached_values >> shift)
+					& ei->reg_mask, ei, reg);
+		}
+	}
+}
+
+
+/*
+ * Setup
+ */
+
+static int __init egpio_probe(struct platform_device *pdev)
+{
+	struct htc_egpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct resource   *res;
+	struct egpio_info *ei;
+	struct gpio_chip  *chip;
+	unsigned int      irq, irq_end;
+	int               i;
+
+	/* Initialize ei data structure. */
+	ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL);
+	if (!ei)
+		return -ENOMEM;
+
+	spin_lock_init(&ei->lock);
+
+	/* Find chained irq */
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (res)
+		ei->chained_irq = res->start;
+
+	/* Map egpio chip into virtual address space. */
+	ei->base_addr = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ei->base_addr))
+		return PTR_ERR(ei->base_addr);
+
+	if ((pdata->bus_width != 16) && (pdata->bus_width != 32))
+		return -EINVAL;
+
+	ei->bus_shift = fls(pdata->bus_width - 1) - 3;
+	pr_debug("bus_shift = %d\n", ei->bus_shift);
+
+	if ((pdata->reg_width != 8) && (pdata->reg_width != 16))
+		return -EINVAL;
+
+	ei->reg_shift = fls(pdata->reg_width - 1);
+	pr_debug("reg_shift = %d\n", ei->reg_shift);
+
+	ei->reg_mask = (1 << pdata->reg_width) - 1;
+
+	platform_set_drvdata(pdev, ei);
+
+	ei->nchips = pdata->num_chips;
+	ei->chip = devm_kcalloc(&pdev->dev,
+				ei->nchips, sizeof(struct egpio_chip),
+				GFP_KERNEL);
+	if (!ei->chip)
+		return -ENOMEM;
+
+	for (i = 0; i < ei->nchips; i++) {
+		ei->chip[i].reg_start = pdata->chip[i].reg_start;
+		ei->chip[i].cached_values = pdata->chip[i].initial_values;
+		ei->chip[i].is_out = pdata->chip[i].direction;
+		ei->chip[i].dev = &(pdev->dev);
+		chip = &(ei->chip[i].chip);
+		chip->label = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+					     "htc-egpio-%d",
+					     i);
+		if (!chip->label)
+			return -ENOMEM;
+
+		chip->parent          = &pdev->dev;
+		chip->owner           = THIS_MODULE;
+		chip->get             = egpio_get;
+		chip->set             = egpio_set;
+		chip->direction_input = egpio_direction_input;
+		chip->direction_output = egpio_direction_output;
+		chip->get_direction   = egpio_get_direction;
+		chip->base            = pdata->chip[i].gpio_base;
+		chip->ngpio           = pdata->chip[i].num_gpios;
+
+		gpiochip_add_data(chip, &ei->chip[i]);
+	}
+
+	/* Set initial pin values */
+	egpio_write_cache(ei);
+
+	ei->irq_start = pdata->irq_base;
+	ei->nirqs = pdata->num_irqs;
+	ei->ack_register = pdata->ack_register;
+
+	if (ei->chained_irq) {
+		/* Setup irq handlers */
+		ei->ack_write = 0xFFFF;
+		if (pdata->invert_acks)
+			ei->ack_write = 0;
+		irq_end = ei->irq_start + ei->nirqs;
+		for (irq = ei->irq_start; irq < irq_end; irq++) {
+			irq_set_chip_and_handler(irq, &egpio_muxed_chip,
+						 handle_simple_irq);
+			irq_set_chip_data(irq, ei);
+			irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
+		}
+		irq_set_irq_type(ei->chained_irq, IRQ_TYPE_EDGE_RISING);
+		irq_set_chained_handler_and_data(ei->chained_irq,
+						 egpio_handler, ei);
+		ack_irqs(ei);
+
+		device_init_wakeup(&pdev->dev, 1);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int egpio_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct egpio_info *ei = platform_get_drvdata(pdev);
+
+	if (ei->chained_irq && device_may_wakeup(&pdev->dev))
+		enable_irq_wake(ei->chained_irq);
+	return 0;
+}
+
+static int egpio_resume(struct platform_device *pdev)
+{
+	struct egpio_info *ei = platform_get_drvdata(pdev);
+
+	if (ei->chained_irq && device_may_wakeup(&pdev->dev))
+		disable_irq_wake(ei->chained_irq);
+
+	/* Update registers from the cache, in case
+	   the CPLD was powered off during suspend */
+	egpio_write_cache(ei);
+	return 0;
+}
+#else
+#define egpio_suspend NULL
+#define egpio_resume NULL
+#endif
+
+
+static struct platform_driver egpio_driver = {
+	.driver = {
+		.name = "htc-egpio",
+		.suppress_bind_attrs = true,
+	},
+	.suspend      = egpio_suspend,
+	.resume       = egpio_resume,
+};
+
+static int __init egpio_init(void)
+{
+	return platform_driver_probe(&egpio_driver, egpio_probe);
+}
+/* start early for dependencies */
+subsys_initcall(egpio_init);